Used by various SVN::TeamTools modules to access the index.
See the 'Indexer' module for more information on how to use the index.
The SvnIndex distinguished revisions,
documents and links.
A revision contains the revision log message and lists of added and deleted files.
A document is a file within the repository.
The 'link' type was introduced to save space and processing power.
If a large trunk is copied to a branch for a development project,
in general only a limited amount of files is actually modified.
In this example,
all files contained by the trunk will be created as linked objects in the new branch (in the search index).
All routines within SVN::TeamTools automatically extend search results (on documents) with all their linked objects.
As soon a the file in the branch is modified (and committed),
the link is removed and the file is stored in the search index as a document.